The invention relates to filler-containing acrylic and modacrylic fibres and a process for the production thereof in which silane-modified silica sols are reacted together with the fibre raw material under specific processing conditions to form a spinnable solution, and this solution is spun.
It is already known to disperse inorganic materials in organic solvents and then to spin them together with acrylonitrile copolymers (DE-OS No. 32 44 028). The filler-containing fibres produced in this way demonstrate reduced flammability and are suitable as reinforcing fibres in building materials or friction materials (brake and clutch linings). In the formerly known processes, the production of a stable dispersion of the highly dispersed solid inorganic filler in the organic medium is accompanied by considerable problems so that expensive apparatus such as high-speed dispersion apparatuses, extruders or bead mills have to be used for the dispersion operation.